High potency vitamins, particularly the antioxidant ones, are regularly consumed as the health benefits of these vitamins are increasingly acknowledged in the scientific and lay press. However, as the high potency tablets grow larger and larger they approach the limits of swallowability. One way to limit the growth in the size of the tablets is to put more active vitamins with less carriers. To make the oil-soluble vitamins, such as vitamin E, suitable for tabletting they must be combined with some kind of carrier to form a tablettable powder where the oil does not interfere with tabletting. Additionally, the carrier must act as binder with other ingredients within the tablet. Up until now the limit of the content of vitamin E in such carriers has been around 75% (750 international units (IU)/g). However, high edible oil (e.g. vitamin E) loading results in tablets with poor characteristics such as low hardness, incomplete disintegration, oil spots on the tablets, oil inhibition of dissolution of trace components in the tablets. The art has attempted to solve the problems with high oil loading tablettable powders.
Specifically, U.S. Pat. No. 3,564,097 (Hoffman-La Roche) discloses multivitamin tablets containing high potency vitamin E (35 to 65% by weight) and an inert carrier such as hydrolyzed gelatin. Tricalcium phosphate is used as an excipient to enhance stability against cracking and oil bleeding.
U.S. Pat. No. 3,608,083 (Hoffman-La Roche) discloses high potency vitamin E powders having 40 to 60% by weight vitamin E and hydrolyzed gelatin. The high potency vitamin E powder is prepared by emulsifying the vitamin E and the hydrolyzed gelatin and then spray drying the emulsion.
U.S. Pat. No. 3,646,192 (Hoffman-La Roche) discloses multivitamin tablets containing high potency vitamin E (35 to 65% by weight) and an inert carrier such as hydrolyzed gelatin. Silica is used as an excipient to enhance stability against cracking and oil bleeding.
U.S. Pat. No. 3,947,596, U.S. Pat. No. 3,959,472, U.S. Pat. No. 3,914,430 and U.S. Pat. No. 3,962,384 (all assigned to Hoffman-La Roche) disclose spray drying processes for preparing a tablettable fat-soluble vitamin powder. The fat-soluble vitamin is about 60% by weight of the powder. Said powder is prepared by blending the fat-soluble vitamin with hydrolyzed gelatin in a sonic homogeneizer (e.g. Homo-Mixer.RTM.) to achieve an emulsion having a particle size of 1 to 3 microns. Said emulsion is then spray dried. Further, glidants (silicates) must be introduced into the spray chamber to prevent adhesion of the emulsion particles to the walls of the dryer.
U.S. Pat. No. 3,932,634 discloses an oil soluble vitamin solution comprising 10 to 55% oil soluble vitamins and dispersing agents such as polyoxyethylene sorbitan monooleate and polyethylene glycol 400 monooleate.
U.S. Pat. No. 4,711,894 (assigned to Henkel) discloses a dry free-flowing vitamin E powder comprising 20 to 60% vitamin E and 40 to 80% carrier selected from gelatin (preferably hydrolyzed) silica, starches or gums and a stabilizer selected from hydroxy or amino acids. Said vitamin powder is prepared by spray drying.
U.S. Pat. No. 4,870,196 discloses a method of preparing a free-flowing vitamin E powder by melting the vitamin E and wax and emulsifiers and powdering agents and spraying this mixture to form droplets.
U.S. Pat. No. 4,892,889 (assigned to BASF) discloses a process for making compressible (tablettable) vitamin powders. Said vitamin powder comprises 20 to 60% vitamin E and 6 to 46% non-hydrolyzed gelatin. An effective amount of a carbohydrate such as lactose or corn syrup or mannitol is added to the vitamin/gelatin emulsion, to aid in creating a stable emulsion. Said emulsion is suitable for spray drying to prepare the vitamin powder. Silicon dioxide is injected into the spray drying chamber to improve flowability of the powder.
U.S. Pat. No. 5,120,761 (assigned to BASF) discloses a free flowing spray dried vitamin E powder comprising 50% vitamin E and partially hydrolyzed gelatin.
U.S. Pat. No. 5,478,569 (assigned to Hoffman-La Roche) discloses powdered fat-soluble vitamin compositions comprising approximately 55% vitamin E and fish gelatin. The powder is prepared by spray drying an emulsion of the vitamin and the gelatin. The particle size of the emulsion is about 0.3 .mu. to 0.6 .mu..
Vitamin E for tabletting is generally sold in a powder form. The commercial standard is 500 iu/gram. Vitamin E is 1000 iu/gram in pure form. Therefore, a 500 iu/gram powder consists of 50% vitamin E oil. Recently, however, a powder which comprises 75% vitamin E and carriers such as fish gelatin, calcium silicate and silicon dioxide, is currently sold by Hoffmann-La Roche, Inc. This product has just been made recently available.
Surprisingly, Applicants have improved on the art of high oil loading tablettable powders. Specifically, Applicant's high oil loading tablettable powders are less greasy than currently available products; have better tabletting properties; and the oil loading can be as high as 90% to deliver more active ingredient in a smaller tablet.
Also, there are processing advantages to the present invention. At higher loadings of the active ingredient, less carrier is required which leads to cost savings. Since there is less carrier, less water is necessary to dissolve the carrier. Therefore, less energy is necessary to dry the powder and greater throughput is achieved. Because hydrolyzed or partially hydrolyzed gelatin is no longer needed, the extra processing cost and the need to control that processing step is obviated. Finally, the preparation of the present invention can be carried out in a "conventional" spray-dryer, i.e. cool air zone modified spray drying is not necessary because atomized droplet formation is not a problem. Thus, costly equipment modification is also obviated.